1. Field of the Invention
The present invention relates to an air gun firing system for use in an air gun.
2. Description of Related Art
Rifle shooting contests using air guns are a common recreational pastime. Air guns are divided into single-loaders and semiautomatic or fully automatic repeating guns.
A conventional air gun has a barrel with a bullet chamber, accommodating a bullet to be fired. A guiding tube is set on the barrel, guiding bullets that fall into the bullet chamber to be fired. However, the bullets have low weights and consequently fall into the bullet chamber only at a relatively low feeding rate. During continuous operation only a limited firing rate of bullets is possible, which is below 180 bullets per minute. A higher firing rate leads to attempted firing although the bullet to be fired has not yet entered the bullet chamber, so that automatic firing will be interrupted. Continuous firing of automatic repeating rifles is thus limited to the feeding rate of bullets into the bullet chamber, which is about 180 bullets per minute.
Conventional semi-automatic repeating air guns in principle work like gunpowder-driven rifles. A lock is driven back by gas pressure upon firing a bullet, which is a simple structure. However, since gas pressure directly drives the firing, firing is too fast with no way of being slowed. Therefore only one bullet can be fired at a time. Although semi-automatic repeating rifles have simple structures, restriction to firing of single bullets do not fulfill demands of users.
A conventional fully automatic repeating gun of another type has a bi-directional gas pressure vessel for driving bullets to be fired. Entering of gas into the gas pressure vessel is controlled by an electromagnetic control valve to achieve fully automatic repeated firing. Combining the control valve with the bi-directional gas pressure vessel allows to control the firing rate of the bullets and to stay within the limit set by the feeding rate of bullets.
However, since a bi-directional gas pressure vessel for driving bullets is used, this type of fully automatic repeating gun has a complicated structure, with the bullets occupying a large volume. Furthermore, after a bullet has entered the bullet chamber, the control valve is pushed by a firing device and opens, letting gas with high pressure into the bullet chamber to fire the bullet. Conventional control valves are not cast in a mold and do not allow to be tested for leaks before being used in air guns. Leaks detected only after having completed the air gun require the air gun to be disassembled and assembled again, which makes producing air guns difficult.
It is the main object of the present invention to provide an air gun firing system with a simple structure and fully automatic repeating operation.
Another object of the present invention is to provide an air gun firing system which does not require a bi-directional gas pressure vessel for simpler control.
A further object of the present invention is to provide an air gun firing system which has a control valve cast in a mold for better reliability.
The present invention can be more fully understood by reference to the following description and accompanying drawings.